Hello, I have run into an issue with Exchange 2007 coexisting with 2003. The 2007 server can send messages to itself and out to external addresses. However, the 2007 server cannot send mail to the 2003 server and the 2003 server cannot send mail to the 2007 server. I have removed and recreated the routing group connector and have even gone so far as to remove and re-install the Hub Transport Role on the 2007 server. So far, no matter what I try the results are the same. The Exchange 2007 server is running SP1.In the Applicaiton log I am getting the following events:MSExchangeTransport 5009 Microsoft Exchange cannot find the route to mailbox database (CN of public folder on 2003 server)MSExchangeSA 2035 The e-mail address description object in the Microsoft Exchange directory for the 'CCMAIL' address type on 'AMD64' machines is missing.MSExchangeIS Public Store3113 There was a problem retrieving the list of public MDBs associated with the TLH with GUID "AAA91D64-1A3E-4EC5-8357-31D3841C0C89". The entry(CN ofpublic store on 2003 server)was not found in the directory. Theitemmay have been deleted.This problem may resolve itself after directory replication and regular directory maintenence completes.MSExchange ADAccess 2159 Process edgetransport.exe (Transport) (PID=3236). Configuration object (CN path for configuration data of 2003 server) failed validation and will be excluded from the result set. Set event logging level for Validation category to Maximum to get additional events about each failure.Also, when mail is sent from the 2003 server to the 2007 server, a NDR is received on the 2003 server saying: "The e-mail address could not be found. Perhaps the recipient moved to a different e-mail organization, or there was a mistake in the address. Check the address and try again."If anyone has any suggestions on anything to try, please share.

I think you have a problem with RUS.run exbpa and see if you get any more clues about the problem.lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com

RUS seems ok. I turned up the logging level to maximum on the 2003 and 2007 servers and choose rebuild for RUS in ESM on the 2003 server.One thing I did run across today, there is not a WINS server on the network. The 2003 server is a cluster, the 2007 server will not be clustered. Is a WINS server needed for Exchange 2007? I don't think that it is, but what about during the coexistance phase with a 2003 cluster? Anyone know?

We have figured it out! The "Allow Inheritable Permissons" checkbox was unchecked on the 2003 server that we were using as the bridgehead for routing group connectors. After changing that mail flow works great.

hi,wins is not required...regards,Mumin CICEK | Exchange - MVP | www.cozumpark.com | www.mumincicek.com

THANK YOU!!! That fixed my exact issue. Whole afternoon of annoyingly no other help anywhere.